Solid-state imaging device, manufacturing method thereof, and camera with alternately arranged pixel combinations

ABSTRACT

A solid-state imaging device includes: photodiodes formed for pixels arranged on a light sensing surface of a semiconductor substrate; a signal reading unit formed on the semiconductor substrate to read a signal charge or a voltage; an insulating film formed on the semiconductor substrate and including optical waveguides; color filters formed on the insulating film; and on-chip lenses formed on the color filters. The first and second pixel combinations are alternately arranged both in the horizontal and vertical directions, the first pixel combination having a layout in which two green pixels are arranged both in the horizontal and vertical directions and a total of four pixels are arranged, the second pixel combination having a layout in which two pixels are arranged both in the horizontal and vertical directions, a total of four pixels are arranged, and two red pixels and two blue pixels are arranged cater cornered.

The present application claims priority to Japanese Patent ApplicationNo. JP 2009-173127, filed in the Japanese Patent Office on Jul. 24,2009, the entire content of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a solid-state imaging device, amanufacturing method thereof, and a camera, and particularly to asolid-state imaging device in which pixels having photodiodes on thelight sensing surfaces thereof are arranged in a matrix shape, amanufacturing method thereof, and a camera which includes thesolid-state imaging device.

2. Description of the Related Art

There has been a problem that in a solid-state imaging device, itbecomes more difficult to efficiently transmit the incident light to aphotoelectric converting unit as the pixel size is reduced, whichresults in lowering the sensitivity.

In order to solve this problem, Japanese Unexamined Patent ApplicationPublication No. 2004-221532 proposed a technique in which an opticalwaveguide was provided above a light sensing unit and below an on-chiplens (OCL) in one pixel in order to reduce a light propagation loss.

The Bayer arrangement has been known widely as a color filterarrangement for pixels of the solid-state imaging device.

For example, the OCL is formed for each pixel, and the optical waveguideis formed between the photodiode and the OCL for each pixel. Inaddition, each pixel has the photodiode with a same area.

In the solid-state imaging device with the above-describedconfiguration, the shape of the OCL is the same as that of the opticalwaveguide for the pixels with respective colors of the color filters.

In addition, a configuration in which the shape of the OCL is changedfor each color of the color filter has been also known as disclosed inJapanese Unexamined Patent Application Publication No. 2008-172091.

Since the CMOS process which has high affinity with a logic circuit isemployed in the CMOS image sensor, there is an advantage in that aperipheral circuit such as a digital signal processor can be mounted ona same semiconductor chip.

The peripheral circuit has been devised in order to reduce its occupyingarea as much as possible by using a multi-layer wiring, such as afour-layer wiring.

If the number of the wiring layers is increased for the pixels alongwith the numbers of those for the peripheral circuit, the distancebetween the semiconductor substrate on which the photodiodes (PD) areformed and the OCL becomes longer, which may lower the light collectionefficiency.

In addition, with regard to a camera module for a mobile phone, it isnecessary to lower the height of the module in order to downsize theentire size and the thickness of the mobile phone.

For this expectation, the angle of a light beam, which is incident tothe periphery of the angle of view of the mounted image sensor, tends tobe wider.

If the obliquely incident light in the periphery of the angle of view isnot efficiently guided to the photodiodes, there may occur a greatdifference in the sensitivities between the periphery of the angle ofview and the center of the angle of view, which results in a so-calledshading which is the deterioration in the pixel characteristic.

Generally, in the formation of the color filters, the color filters ofadjacent pixels may possibly overlap with each other if the colorarrangements are different in the adjacent pixels. The overlappedportion blocks the light transmission, and becomes a non-effectiveregion.

Specifically, when the adjacent pixels of the green pixel (G) are thered pixel (R) and the blue pixel (B) in the Bayer arrangement, the colorfilters for G and B and the color filters for G and R are respectivelyoverlapped in the adjacent parts, and the overlapped portions becomenon-effective regions.

In addition, if the opening of the optical waveguide becomes smaller,the light collection effect may possibly be lowered.

In Japanese Unexamined Patent Application Publication Nos. 58-175372,2000-69491, and 5-243543, for example, there are descriptions ofsolid-state imaging devices in each of which pixels with photodiodesprovided on their light sensing surfaces are arranged in a matrix shape.

SUMMARY OF THE INVENTION

As described above, there has been a problem that the overlapping of thecolor filters causes non-effective regions in the solid-state imagingdevice such as the CMOS image sensor in the related art.

A solid-state imaging device according to an embodiment of the presentinvention includes: photodiodes which are formed separately for eachpixel arranged in a matrix shape on a light sensing surface of asemiconductor substrate; a signal reading unit which is formed on thesemiconductor substrate and reads a signal charge generated and chargedin the photodiodes or a voltage in accordance with the signal charge; aninsulating film which is formed on the semiconductor substrate so as tocover the photodiodes and includes optical waveguides; color filterswhich are formed on the insulating film; and on-chip lenses which areformed on the color filters. In addition, in a layout, first pixelcombinations and second pixel combinations are alternately arranged bothin horizontal and vertical directions, each of the first pixelcombinations having a layout in which two green pixels are arranged bothin horizontal and vertical directions and a total of four pixels arearranged while provided with a green color filter as their color filter,each of the second pixel combinations having a layout in which twopixels are arranged both in the horizontal and vertical directions, atotal of four pixels are arranged, and two red pixels having red colorfilters and two blue pixels having blue color filters are arranged catercornered.

In the above solid-state imaging device, the photodiodes are formedseparately for each pixel arranged in a matrix shape on the lightsensing surface of a semiconductor substrate, and the signal readingunit which reads a signal charge generated and charged in thephotodiodes or a voltage in accordance with the signal charge is formedon the semiconductor substrate. In addition, the insulating filmincluding the optical waveguides is formed on the semiconductorsubstrate so as to cover the photodiodes, the color filters are formedon the insulating film, and the on-chip lenses are formed on the colorfilters.

Here, in the layout of the color filters, the first pixel combinationsand the second pixel combinations are alternately arranged both inhorizontal and vertical directions, the first pixel combination having alayout in which two green pixels are arranged both in the horizontal andvertical directions and a total of four pixels are arranged whileprovided with a green color filter as their color filter, the secondpixel combination having a layout in which two pixels are arranged bothin the horizontal and vertical directions, a total of four pixels arearranged, and two red pixels having red color filters and two bluepixels having blue color filters are arranged cater cornered.

In addition, a solid-state imaging device according to anotherembodiment of the present invention includes: photodiodes which areformed separately for each pixel arranged in a matrix shape on a lightsensing surface of a semiconductor substrate; a signal reading unitwhich is formed on the semiconductor substrate and reads a signal chargegenerated and charged in the photodiodes or a voltage in accordance withthe signal charge; an insulating film which is formed on thesemiconductor substrate so as to cover the photodiodes and includesoptical waveguides; color filters which are formed on the insulatingfilm; and on-chip lenses which are formed on the color filters. Here,the color filters include first pixel combinations in each of which twogreen pixels are arranged both in the horizontal and vertical directionsand a total of four pixels are arranged while provided with a greencolor filter as their color filter, second pixel combinations in each ofwhich two blue pixels are arranged both in the horizontal and verticaldirections and a total of four pixels are arranged while provided with ablue color filter as their color filter, and third pixel combinations ineach of which two red pixels are arranged both in the horizontal andvertical directions and a total of four pixels are arranged whileprovided with a red color filter as their color filter. Moreover, in alayout, fourth pixel combinations, in each of which the first pixelcombinations and the second pixel combinations are alternately arrangedin the horizontal direction, and fifth pixel combinations, in each ofwhich the first pixel combinations and the third pixel combinations arealternately arranged in the horizontal direction, are alternatelyarranged in the vertical direction so as to shift by the amount of thefirst pixel combination in the horizontal direction. Furthermore, oneon-chip lens is formed for each of the first pixel combination, thesecond pixel combination, and the third pixel combination as the on-chiplens.

In the above solid-state imaging device, the photodiodes are formedseparately for each pixel arranged in a matrix shape on the lightsensing surface of a semiconductor substrate, and the signal readingunit which reads a signal charge generated and charged in thephotodiodes or a voltage in accordance with the signal charge is formedon the semiconductor substrate. In addition, the insulating filmincluding the optical waveguides is formed on the semiconductorsubstrate so as to cover the photodiodes, the color filters are formedon the insulating film, and the on-chip lenses are formed on the colorfilters.

Here, the color filters include the first pixel combinations in each ofwhich two green pixels are arranged both in the horizontal and verticaldirections and a total of four pixels are arranged while provided with agreen color filter as their color filter, the second pixel combinationsin each of which two blue pixels are arranged both in the horizontal andvertical directions and a total of four pixels are arranged whileprovided with a blue color filter as their color filter, and the thirdpixel combinations in each of which two red pixels are arranged both inthe horizontal and vertical directions and a total of four pixels arearranged while provided with a red color filter as their color filter.Moreover, in a layout, the fourth pixel combinations, in each of whichthe first pixel combinations and the second pixel combinations arealternately arranged in the horizontal direction, and the fifth pixelcombinations, in each of which the first pixel combinations and thethird pixel combinations are alternately arranged in the horizontaldirections, are alternately arranged in the vertical direction so as toshift by the amount of the first pixel combination in the horizontaldirection.

Furthermore, one on-chip lens is formed for each of the first pixelcombination, the second pixel combination, and the third pixelcombination as the on-chip lens.

A method of manufacturing a solid-state imaging device according to anembodiment of the present invention includes the steps of: formingphotodiodes separately for each pixel arranged in a matrix shape on alight sensing surface of a semiconductor substrate and a signal readingunit for reading a signal charge generated and charged in thephotodiodes or a voltage in accordance with the signal charge; formingan insulating film including optical waveguides on the semiconductorsubstrate so as to cover the photodiodes; forming color filters on theinsulating film; and forming on-chip lenses on the color filters. Here,in the step of forming the color filters, a layout in which the firstpixel combinations and the second pixel combinations are alternatelyarranged both in the horizontal and vertical directions is employed, thefirst pixel combination having a layout in which two green pixels arearranged both in the horizontal and vertical directions and a total offour pixels are arranged while provided with a green color filter astheir color filter, the second pixel combination having a layout inwhich two pixels are arranged both in the horizontal and verticaldirections, a total of four pixels are arranged, and two red pixelshaving red color filters and two blue pixels having blue color filtersare arranged cater cornered.

In the above method of manufacturing the solid-state imaging device, thephotodiodes are formed separately for each pixel arranged in a matrixshape on the light sensing surface of a semiconductor substrate, and thesignal reading unit which reads a signal charge generated and charged inthe photodiodes or a voltage in accordance with the signal charge isformed on the semiconductor substrate. Next, the insulating filmincluding the optical waveguides is formed on the semiconductorsubstrate so as to cover the photodiodes, the color filters are formedon the insulating film, and the on-chip lenses are formed on the colorfilters.

Here, in the step of forming the color filters, a layout in which thefirst pixel combinations and the second pixel combinations arealternately arranged both in the horizontal and vertical directions isemployed, the first pixel combination having a layout in which two greenpixels are arranged both in the horizontal and vertical directions and atotal of four pixels are arranged while provided with a green colorfilter as their color filter, the second pixel combination having alayout in which two pixels are arranged both in the horizontal andvertical directions, a total of four pixels are arranged, and two redpixels having red color filters and two blue pixels having blue colorfilters are arranged cater cornered.

In addition, a method of manufacturing a solid-state imaging deviceaccording to an embodiment of the present invention includes the stepsof: forming photodiodes separately for each pixel arranged in a matrixshape on a light sensing surface of a semiconductor substrate and asignal reading unit for reading a signal charge generated and charged inthe photodiodes or a voltage in accordance with the signal charge;forming an insulating film including optical waveguides on thesemiconductor substrate so as to cover the photodiodes; forming colorfilters on the insulating film; and forming on-chip lenses on the colorfilters. Here, in the step of forming the color filters, the colorfilters include first pixel combinations, in each of which two greenpixels are arranged both in the horizontal and vertical directions and atotal of four pixels are arranged while provided with a green colorfilter as their color filter, second pixel combinations, in each ofwhich two blue pixels are arranged both in the horizontal and verticaldirections and a total of four pixels are arranged while provided with ablue color filter as their color filter, and third pixel combinations,in each of which two red pixels are arranged both in the horizontal andvertical directions and a total of four pixels are arranged whileprovided with a red color filter as their color filter. In addition, ina layout, fourth pixel combinations, in each of which the first pixelcombinations and the second pixel combinations are alternately arrangedin the horizontal direction, and fifth pixel combinations, in each ofwhich the first pixel combinations and the third pixel combinations arealternately arranged in the horizontal direction, are alternatelyarranged in the vertical direction so as to shift by the amount of thefirst pixel combination in the horizontal direction. Moreover, in thestep of forming the on-chip lens, one on-chip lens is formed for each ofthe first pixel combination, the second pixel combination, and the thirdpixel combination as the on-chip lens.

In the above method of manufacturing the solid-state imaging device, thephotodiodes are formed separately for each pixel arranged in a matrixshape on the light sensing surface of a semiconductor substrate, and thesignal reading unit which reads a signal charge generated and charged inthe photodiodes or a voltage in accordance with the signal charge isformed on the semiconductor substrate. Next, the insulating filmincluding the optical waveguides is formed on the semiconductorsubstrate so as to cover the photodiodes, the color filters are formedon the insulating film, and the on-chip lenses are formed on the colorfilters.

Here, in the step of forming the color filters, the color filtersinclude first pixel combinations, in each of which two green pixels arearranged both in the horizontal and vertical directions and a total offour pixels are arranged while provided with a green color filter astheir color filter, second pixel combinations, in each of which two bluepixels are arranged both in the horizontal and vertical directions and atotal of four pixels are arranged while provided with a blue colorfilter as their color filter, and third pixel combinations, in each ofwhich two red pixels are arranged both in the horizontal and verticaldirections and a total of four pixels are arranged while provided with ared color filter as their color filter. In addition, in a layout, fourthpixel combinations, in each of which the first pixel combinations andthe second pixel combinations are alternately arranged in the horizontaldirection, and fifth pixel combinations, in each of which the firstpixel combinations and the third pixel combinations are alternatelyarranged in the horizontal direction, are alternately arranged in thevertical direction so as to shift by the amount of the first pixelcombination in the horizontal direction.

Moreover, in the step of forming the on-chip lens, one on-chip lens isformed for each of the first pixel combination, the second pixelcombination, and the third pixel combination as the on-chip lens.

A camera according to an embodiment of the present invention includes: asolid-state imaging device in which a plurality of pixels are integratedon a light sensing surface; an optical system which guides incidentlight to an imaging unit of the solid-state imaging device; and a signalprocessing circuit which processes output signals of the solid-stateimaging device. Here, the solid-state imaging device includesphotodiodes which are formed separately for each pixel arranged in amatrix shape on a light sensing surface of a semiconductor substrate, asignal reading unit which is formed on the semiconductor substrate andreads a signal charge generated and charged in the photodiodes or avoltage in accordance with the signal charge, an insulating film whichis formed on the semiconductor substrate so as to cover the photodiodesand includes optical waveguides, color filters which are formed on theinsulating film, and on-chip lenses which are formed on the colorfilters. In addition, in a layout of the color filters, first pixelcombinations and second pixel combinations are alternately arranged bothin the horizontal and vertical directions, the first pixel combinationhaving a layout in which two green pixels are arranged both in thehorizontal and vertical directions and a total of four pixels arearranged while provided with a green color filter as their color filter,the second pixel combination having a layout in which two pixels arearranged both in the horizontal and vertical directions, a total of fourpixels are arranged, and two red pixels having red color filters and twoblue pixels having blue color filters are arranged cater cornered.

In addition, a camera according to an embodiment of the presentinvention includes: a solid-state imaging device in which a plurality ofpixels are integrated on a light sensing surface; an optical systemwhich guides incident light to an imaging unit of the solid-stateimaging device; and a signal processing circuit which processes outputsignals of the solid-state imaging device. Here, the solid-state imagingdevice includes photodiodes which are formed separately for each pixelarranged in a matrix shape on a light sensing surface of a semiconductorsubstrate, a signal reading unit which is formed on the semiconductorsubstrate and reads a signal charge generated and charged in thephotodiodes or a voltage in accordance with the signal charge, aninsulating film which is formed on the semiconductor substrate so as tocover the photodiodes and includes optical waveguides, color filterswhich are formed on the insulating film, and on-chip lenses which areformed on the color filters. In addition, color filters include firstpixel combinations in each of which two green pixels are arranged bothin the horizontal and vertical directions and a total of four pixels arearranged while provided with a green color filter as their color filter,second pixel combinations in each of which two blue pixels are arrangedboth in the horizontal and vertical directions and a total of fourpixels are arranged while provided with a blue color filter as theircolor filter, and third pixel combinations in each of which two redpixels are arranged both in the horizontal and vertical directions and atotal of four pixels are arranged while provided with a red color filteras their color filter. Moreover, in a layout, fourth pixel combinations,in each of which the first pixel combinations and the second pixelcombinations are alternately arranged in the horizontal direction, andfifth pixel combinations, in each of which the first pixel combinationsand the third pixel combinations are alternately arranged in thehorizontal direction, are alternately arranged in the vertical directionso as to shift by the amount of the first pixel combination in thehorizontal direction. Furthermore, one on-chip lens is formed for eachof the first pixel combination, the second pixel combination, and thethird pixel combination as the on-chip lens.

The above-described camera includes a solid-state imaging device inwhich a plurality of pixels are integrated on a light sensing surface;an optical system which guides incident light to an imaging unit of thesolid-state imaging device; and a signal processing circuit whichprocesses output signals of the solid-state imaging device. Here, thesolid-state imaging device is the one with the above configurationaccording to the embodiment of the present invention.

According to the solid-state imaging device of the embodiment of thisinvention, it is possible to reduce the overlapping of the color filtersat the pixel border in a first pixel combination which is constituted byat least green pixels, reduce the non-effective regions, and therebyenhance sensitivity.

According to the manufacturing method of the solid-state imaging deviceof the embodiment of the present invention, it is possible tomanufacture the solid-state imaging device which can reduce theoverlapping of the color filters at the pixel border in a first pixelcombination which is constituted by at least green pixels, reduce thenon-effective regions, and thereby enhance sensitivity.

According to the solid-state imaging device which constitutes the cameraof the embodiment of this invention, it is possible to reduce theoverlapping of the color filters at the pixel border in a first pixelcombination which is constituted by at least green pixels, reduce thenon-effective regions, and thereby enhance sensitivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are plan views illustrating a layout of pixels andon-chip lenses of a solid-state imaging device according to a firstembodiment of the present invention;

FIGS. 2A and 2B are schematic sectional views of the solid-state imagingdevice according to the first embodiment of the present invention;

FIGS. 3A and 3B are sectional views illustrating the configuration ofthe color filters according to the first embodiment of the presentinvention;

FIGS. 4A and 4B are plan views illustrating a layout of pixels andon-chip lenses of a solid-state imaging device according to a firstmodified example of the present invention;

FIGS. 5A and 5B are plan views illustrating a layout of pixels andon-chip lenses of a solid-state imaging device according to a secondmodified example of the present invention;

FIGS. 6A and 6B are plan views illustrating a layout of pixels andon-chip lenses of a solid-state imaging device according to a secondembodiment of the present invention;

FIG. 7A is a plan view illustrating a layout of pixels and on-chiplenses of a solid-state imaging device according to a third embodimentof the present invention;

FIG. 7B is an equivalent circuit diagram of the pixels;

FIG. 8 is a plan view illustrating a layout of pixels and on-chip lensesof the solid-state imaging device according to the third embodiment ofthe present invention;

FIG. 9 is a plan view illustrating a layout of pixels and on-chip lensesof a solid-state imaging device according to a fourth embodiment of thepresent invention;

FIG. 10 is a plan view illustrating a layout of pixels of a solid-stateimaging device according to a fifth embodiment of the present invention;

FIG. 11 is a plan view illustrating a layout of pixels according to afirst working example of the present invention;

FIG. 12 is a plan view illustrating a layout of pixels according to asecond working example of the present invention;

FIG. 13 is a plan view illustrating a layout of pixels according to athird working example of the present invention;

FIG. 14 is a plan view illustrating a layout of pixels according to afourth working example of the present invention; and

FIG. 15 is a schematic configuration diagram of a camera according to asixth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the description will be made of the solid-state imagingdevice, the manufacturing method thereof, and the camera which includesthe solid-state imaging device according to the embodiments of thepresent invention with reference to the accompanying drawings.

In this regard, the description will be made in the following order:

1. First Embodiment (Configuration in Which Two Green Pixels AreArranged Both in Horizontal and Vertical Directions and Total of FourGreen Pixels Are Arranged)

2. First Modified Example

3. Second Modified Example

4. Second Embodiment (Configuration in Which Each of Green, Blue, andRed Pixels Are Arranged by Two Both in Horizontal and VerticalDirections and Total of Four of Respective Color Pixels Are Arranged)

5. Third Embodiment (Configuration in Which a Floating Diffusion IsShared Between Pixels)

6. Fourth Embodiment (Configuration of Upper Layer Wiring)

7. Fifth Embodiment (Configuration in Which Pluralities of Green PixelsAre Arranged in First and Second Directions)

8. First Working Example

9. Second Working Example

10. Third Working Example

11. Fourth Working Example

12. Sixth Embodiment (Camera Employing Solid-State Imaging Device)

First Embodiment

[Overall Configuration of Solid-State Imaging Device]

FIG. 1A is a plan view illustrating a pixel layout of the solid-stateimaging device according to this embodiment.

In the solid-state imaging device according to this embodiment,photodiodes are formed separately for each pixel arranged on a lightsensing surface of a semiconductor substrate in a matrix shape. Inaddition, a signal reading unit for reading a signal charge generatedand charged in the photodiodes and a voltage in accordance with thesignal charge is formed on the semiconductor substrate. Moreover, aninsulating film including an optical waveguide is formed on thesemiconductor substrate so as to cover the photodiode, a color filter isformed on the insulating film, and an on-chip lens is formed on thecolor filter.

[Layout of Color Filters and On-Chip Lenses]

The layout shown in FIG. 1A is an example of the layout of the colorfilters.

That is, there are first pixel combinations 1 and second pixelcombinations 2. The first pixel combination 1 includes a configurationin which two green pixels (G) are arranged both in the horizontal andvertical directions and a total of four green pixels are arranged whileprovided with a green color filter. The second pixel combination 2 hasconfiguration in which two pixels are arranged both in the horizontaland vertical directions and a total of four pixels are arranged, and twored pixels (R) having red color filters and two blue pixels (B) havingblue color filters are arranged cater cornered. In the layout, thesefirst pixel combinations 1 and the second pixel combinations 2 arealternately arranged both in the horizontal and vertical directions.

The layout shown in FIG. 1A can be also understood as a configuration inwhich the pixel layout surrounded by the broken line A is repeatedlyarranged both in the horizontal and vertical directions.

FIG. 1B is a plan view illustrating the pixel layout and an on-chip lenslayout of the solid-state imaging device according to this embodiment.As described above, in the solid-state imaging device according to thisembodiment, an on-chip lens is formed on the color filter.

As shown in FIG. 1B, one on-chip lens OCL_(G)is formed with respect tothe first pixel combination 1 as the on-chip lens.

In addition, one on-chip lens (OCL_(B) or OCL_(R)) is formed withrespect to each pixel of the second pixel combination 2 as the on-chiplens. The diameter of one on-chip lens (OCL_(B) or OCL_(R)) for eachpixel of the second pixel combination 2 is different from the diameterof one on-chip lens OCL_(G) for the first pixel combination 1.

Alternatively, one on-chip lens may be formed for each pixel of thefirst pixel combination 1 in the same manner as in the second pixelcombination 2.

[Layer Configuration of Solid-State Imaging Device]

FIGS. 2A and 2B are schematic sectional views of the solid-state imagingdevice according to this embodiment. These drawings show the sectionalviews taken along the line crossing over the two green pixels (G1, G2),one blue pixel B, and one red pixel R.

FIG. 2A shows the case in which one on-chip lens is formed for the firstpixel combination 1.

In the solid-state imaging device according to this embodiment,separation insulating films 11 for separating the pixels are formed onthe semiconductor substrate 10, and semiconductor regions 12 includingphotodiodes are formed in the area separated by the separationinsulating films 11. As described above, the pixels are arranged andformed in the matrix shape on the light sensing surface of thesemiconductor substrate.

In addition, a signal reading unit (not shown) for reading a signalcharge generated and charged in the photodiodes and voltage inaccordance with the signal charge is formed on the semiconductorsubstrate. This is constituted by a MOS transistor, which is known as afloating diffusion and a source follower in the CMOS image sensor. Inaddition, this is constituted by a CCD channel in the CCD image sensor.

A first insulating film 13 is formed on the semiconductor substrate soas to cover the photodiodes. Conductive layers 14 which constitute theupper layer wiring are embedded in the first insulating film 13 abovethe region where the separation insulating films 11 are formed.

In addition, openings 15 are formed in the first insulating film 13above the photodiodes. Second insulating film 16 is formed so as to fillin the openings 15.

The second insulating film 16 is made by a material with a higherrefractive index than that of the first insulating film 13. For example,the first insulating film 13 is made by oxide silicon, silicon nitride,silicon carbide, and the laminated body thereof. The second insulatingfilm 16 is made by a resin with a high refractive index such as siloxaneresin or polyimide, and preferably made by siloxane resin.

In addition, the above-described resin contains metal oxides particlessuch as titanium oxide, tantalum oxide, niobium oxide, tungsten oxide,zirconium oxide, zinc oxide, indium oxide, or hafnium oxide, whichincreases the refractive index.

With the above configuration in which the insulating film with a highrefractive index (the second insulating film 16) is embedded in theopenings 14 of the insulating film with a low refractive index (thefirst insulating film 12), the optical waveguide for guiding theincident light from the upper direction is formed.

The color filters (17B, 17G, 17R) are formed on the insulating films(12, 16), and the on-chip lens 18 is formed on the color filters (17B,17G, 17R). As shown in FIG. 2A, one on-chip lens 18 is formed for eachfirst pixel combination 1 constituted by the green pixels (G1, G2) andthe like.

Here, as shown in FIG. 2A, one optical waveguide is formed for eachfirst pixel combination 1 as the optical waveguide for the green pixels(G1, G2).

For example, with regard to the optical waveguides, one opticalwaveguide is formed for each pixel of the second pixel combination 2,and one opening size of the optical waveguide for each pixel of thesecond pixel combination 2 is different from that of the opticalwaveguide for the first pixel combination 1.

On the other hand, FIG. 2B shows the case in which one on-chip lens isformed for each pixel of the first pixel combination 1.

This case is different from the one shown in FIG. 2A in that one on-chiplens is formed for each of the green pixels (G1, G2). Otherconfigurations are substantially the same as that shown in FIG. 2A.

[Configuration of Color Filters]

FIGS. 3A and 3B are schematic views illustrating the configuration ofthe color filters according to this embodiment.

FIG. 3A shows the sectional view of the color filters of the solid-stateimaging device in the related art, and the sectional view taken alongthe line crossing over two blue pixels (B1, B2), two red pixels (R1,R2), and one green pixel G1.

The color filters of the green pixel G1 and the blue pixel B2 areoverlapped with each other, the color filters of the green pixel G1 andthe red pixel R1 are overlapped with each other, and these overlappingportions become non-effective regions. Here, the positional (upper andlower) relationships in the overlapping portions depend on the order inwhich the color filters are formed. The color filters are formed suchthat parts thereof are overlapped with each other at the border area ofthe pixels, which results in the above-described configuration.

On the other hand, FIG. 3B shows a sectional view of the color filtersof the solid-state imaging device according to this embodiment, and thesectional view taken along the line crossing over two blue pixels (B1,B2), two green pixels (G1, G2), and one red pixel R1.

As described above, the color filter according to this embodimentincludes the first pixel combination 1 in which four green pixels areadjacently arranged. Therefore, there is no overlapping portion of thecolor filters in the first pixel combination 1, and thereby it ispossible to reduce the area of the non-effective region and enhancesensitivity.

Particularly, the green light is a light in a region for which people'seyes have high sensitivity. Therefore, it is possible to enhanceluminance data of the obtained image data by improving the sensitivityof the green pixels.

As described above, one optical waveguide is formed for each first pixelcombination 1 as the optical waveguide of the green pixels. With thisconfiguration, it is possible to secure large opening sizes of theoptical waveguides, and enhance the light collection effect.

[Manufacturing Method of Solid-State Imaging Device]

First, the photodiodes are formed separately for each of the pixelswhich are arranged in the matrix shape on the light sensing surface ofthe semiconductor substrate and the signal reading unit for reading thesignal charge generated and charged in the photodiodes and the voltagein accordance with the signal charge. Next, the insulating filmincluding the optical waveguides is formed on the semiconductorsubstrate so as to cover the photodiodes. Then, the color filters areformed on the insulating film, and the on-chip lenses are formed on thecolor filters.

Here, in the step of forming the color filters, the layout having thefirst pixel combinations 1 and the second pixel combinations 2 isemployed. In the first pixel combination 1, two green pixels arearranged both in the horizontal and vertical directions, and a total offour green pixels are arranged while provided with a green color filter.In the second pixel combination 2, two pixels are arranged both in thehorizontal and vertical directions, and a total of four pixels arearranged. In addition, two red pixels having red color filters and twoblue pixels having blue color filters are arranged cater cornered. Thelayout in which the first pixel combinations 1 and the second pixelcombinations 2 are alternately arranged both in the horizontal andvertical directions is employed.

As described above, four adjacent green pixels constitute the firstpixel combination 1, and no overlapping portion comes about in the firstpixel combination 1. Accordingly, it is possible to manufacture thesolid-state imaging device capable of reducing the area of thenon-effective regions and enhancing sensitivity.

Particularly, it is possible to secure the large opening sizes of theoptical waveguides and thereby to enhance the light collection effect byforming one optical waveguide for each first pixel combination 1 as theoptical waveguide for the green pixels.

First Modified Example

[Layout of Color Filters and On-Chip Lenses]

FIG. 4A is a plan view illustrating the pixel layout of the solid-stateimaging device according to this modified example. The solid-stateimaging device according to this modified example is substantially thesame as that of the first embodiment except that the positions of thered pixels (R) having the red color filters are switched with thepositions of the blue pixels (B) having the blue color filters.

That is, the pixel layout includes the first pixel combinations 1 andthe second pixel combinations 2. In the first pixel combination 1, twogreen pixels (G) are arranged both in the horizontal and verticaldirections, and a total of four pixels are arranged while provided witha green color filter. In the second pixel combination 2, two pixels arearranged both in the horizontal and vertical directions, a total of fourpixels are arranged, and two red pixels (R) having the red color filtersand two blue pixels (B) having the blue color filters are arranged catercornered. These first pixel combinations 1 and second pixel combinations2 are alternately arranged in both the horizontal and verticaldirections in the layout.

The layout shown in FIG. 4A can be also understood as a configuration inwhich the pixel layout surrounded by the broken line A is repeatedlyarranged both in the horizontal and vertical directions.

FIG. 4B is a plan view illustrating the pixel layout and the on-chiplens layout of the solid-state imaging device according to this modifiedexample. In the solid-state imaging device according to this modifiedexample, the on-chip lenses are formed on the color filters.

One on-chip lens OCL_(G) is formed for the first pixel combination 1 asthe above-described on-chip lens as shown in FIG. 4B.

In addition, one on-chip lens (OCL_(B) or OCL_(R)) is formed for eachpixel of the second pixel combination 2 as the on-chip lens. Thediameter of one on-chip lens (OCL_(B) or OCL_(R)) for each pixel of thesecond pixel combination 2 is different from that of one on-chip lensOCL_(G) for the first pixel combination 1.

In addition, as the optical waveguide for the green pixel (G), oneoptical waveguide is formed for each first pixel combination 1.

On the other hand, as the optical waveguide, one optical waveguide isformed for each pixel of the second pixel combination 2, and one openingsize of the optical waveguide for each pixel of the second pixelcombination 2 is different from that of the optical waveguide for thefirst pixel combination 1.

As described above, according to the color filter of this modifiedexample, four adjacent green pixels constitute the first pixelcombination 1, and no overlapping portion comes about in the first pixelcombination 1. Accordingly, it is possible to reduce the area of thenon-effective regions and enhance sensitivity.

Particularly, the green light is a light in a region for which people'seyes have high sensitivity. Therefore, it is possible to enhanceluminance data of the obtained image data by improving the sensitivityof the green pixels.

In addition, one optical waveguide is formed for each first pixelcombination 1 as the optical waveguide of the green pixels. With thisconfiguration, it is possible to secure large opening sizes of theoptical waveguides, and enhance the light collection effect.

Second Modified Example

[Layout of Color Filters and On-Chip Lenses]

FIG. 5A is a plan view illustrating the pixel layout of the solid-stateimaging device according to this modified example.

The solid-state imaging device according to this modified example issubstantially the same as that of the first embodiment except that thepositions of the red pixels (R) having the red color filters areswitched with the positions of the blue pixels (B) having the blue colorfilters.

That is, the pixel layout includes the first pixel combinations 1 andthe second pixel combinations 2. In the first pixel combination 1, twogreen pixels (G) are arranged both in the horizontal and verticaldirections, and a total of four pixels are arranged while provided witha green color filter. In the second pixel combination 2, two pixels arearranged both in the horizontal and vertical directions, a total of fourpixels are arranged, and two red pixels (R) having the red color filtersand two blue pixels (B) having the blue color filters are arranged catercornered. These first pixel combinations 1 and second pixel combinations2 are alternately arranged in both the horizontal and verticaldirections in the layout.

The portions where the positions of the red pixels (R) are switched withthe positions of the blue pixels (B) correspond to part of the layoutaccording to the first embodiment. As shown in FIG. 5A, the red pixels(R) and the blue pixels (B) are respectively arranged cater cornered.

The layout shown in FIG. 5A can be also understood as a configuration inwhich the pixel layout surrounded by the broken line A is repeatedlyarranged both in the horizontal and vertical directions.

FIG. 5B is a plan view illustrating the pixel layout and the on-chiplens layout of the solid-state imaging device according to this modifiedexample. In the solid-state imaging device according to this modifiedexample, the on-chip lenses are formed on the color filters.

One on-chip lens OCL_(G) is formed for the first pixel combination 1 asthe above-described on-chip lens as shown in FIG. 5B.

In addition, one on-chip lens (OCL_(B) or OCL_(R)) is formed for eachpixel of the second pixel combination 2 as the on-chip lens. Thediameter of one on-chip lens (OCL_(B) or OCL_(R)) for each pixel of thesecond pixel combination 2 is different from that of one on-chip lensOCL_(G) for the first pixel combination 1.

In addition, as the optical waveguide for the green pixel (G), oneoptical waveguide is formed for each first pixel combination 1.

On the other hand, as the optical waveguide, one optical waveguide isformed for each pixel of the second pixel combination 2, and one openingsize of the optical waveguide for each pixel of the second pixelcombination 2 is different from that of the optical waveguide for thefirst pixel combination 1.

As described above, according to the color filter of this modifiedexample, four adjacent green pixels constitute the first pixelcombination 1, and no overlapping portion comes about in the first pixelcombination 1. Accordingly, it is possible to reduce the area of thenon-effective regions and enhance sensitivity.

Particularly, the green light is a light in a region for which person'seyes have high sensitivity. Therefore, it is possible to enhanceluminance data of the obtained image data by improving the sensitivityof the green pixels.

In addition, one optical waveguide is formed for each first pixelcombination 1 as the optical waveguide of the green pixels. With thisconfiguration, it is possible to secure large opening sizes of theoptical waveguides, and enhance the light collection effect.

Second Embodiment

[Layout of Color Filters and On-Chip Lenses]

FIG. 6A is a plan view illustrating the pixel layout of the solid-stateimaging device according to this embodiment.

The solid-state imaging device according to this embodiment issubstantially the same as that of the first embodiment except for theconfigurations of the color filters, the on-chip lenses, and the opticalwaveguides.

The layout of the pixels provided with the color filters includes thefirst pixel combinations 1, the second pixel combinations 2, and thethird pixel combinations 3. In the first pixel combination 1, two greenpixels are arranged both in the horizontal and vertical directions, andtotal of four pixels are arranged while provided with a green colorfilter. In the second pixel combination 2, two blue pixels are arrangedboth in the horizontal and vertical directions, and a total of fourpixels are arranged while provided with a blue color filter. In thethird pixel combination 3, two red pixels are arranged both in thehorizontal and vertical directions, and a total of four pixels arearranged while provided with a red color filter. Here, the fourth pixelcombination 4 is configured such that the first pixel combinations 1 andthe second pixel combinations 2 are alternately arranged in thehorizontal direction. In addition, the fifth pixel combination 5 isconfigured such that the first pixel combinations 1 and the third pixelcombinations 3 are alternately arranged in the horizontal direction. Inthis layout, the fourth pixel combinations 4 and the fifth pixelcombinations 5 are alternately arrange in the vertical direction so asto shift by the amount of the first pixel combination 1 in thehorizontal direction.

The layout shown in FIG. 6A can be also understood as a configuration inwhich the pixel layout surrounded by the broken line A is repeatedlyarranged both in horizontal and vertical directions.

FIG. 6B is a plan view illustrating the pixel layout and the on-chiplens layout of the solid-state imaging device according to thisembodiment. In the solid-state imaging device according to thisembodiment, the on-chip lenses are formed on the color filters.

One on-chip lens OCL_(G) is formed for the first pixel combination 1 asthe on-chip lens as shown in FIG. 6B.

In addition, one on-chip lens (OCL_(B) or OCL_(R)) is formed for each ofthe second pixel combination 2 and the third pixel combination 3 as theon-chip lens. The diameter of one on-chip lens (OCL_(B) or OCL_(R)) foreach of the second pixel combination 2 and the third pixel combination 3is equal to that of one on-chip lens OCL_(G) for the first pixelcombination 1.

In addition, as the optical waveguide for the green pixel (G), oneoptical waveguide is formed for each first pixel combination 1.

As the optical waveguides, one optical waveguide is formed for each ofthe second pixel combination 2 and the third pixel combination 3, andone opening size of the optical waveguide for each of the second pixelcombination 2 and the third pixel combination 3 is equal to that of theoptical waveguide for the first pixel combination 1.

As described above, according to the color filter of this embodiment,four adjacent green pixels constitute the first pixel combination 1, andno overlapping portion of the color filters comes about in the firstpixel combination 1. Accordingly, it is possible to reduce the area ofthe non-effective regions and enhance sensitivity. In addition, fouradjacent blue pixels and four adjacent red pixels respectivelyconstitute the second pixel combination 2 and the third pixelcombination 3 in the same manner, and no overlapping portion of thecolor filters comes about in the second pixel combination 2 and thethird pixel combination 3. Accordingly, it is possible to reduce thearea of the non-effective regions and enhance sensitivity.

Particularly, the green light is a light in a region for which people'seyes have high sensitivity. Therefore, it is possible to enhanceluminance data of the obtained image data by improving the sensitivityof the green pixels.

In addition, one optical waveguide is formed for each of the first pixelcombination 1, the second pixel combination 2, and the third pixelcombination 3, as the optical waveguides of the green pixels, bluepixels and the red pixels. With this configuration, it is possible tosecure large opening sizes of the optical waveguides, and enhance thelight collection effect.

[Manufacturing Method of Solid-State Imaging Device]

First, the photodiodes are formed separately for each of the pixelsarranged in the matrix shape on the light sensing surface of thesemiconductor substrate and the signal reading unit for reading thesignal charge generated and charged in the photodiodes and the voltagein accordance with the signal charge. Next, the insulating filmincluding the optical waveguides is formed on the semiconductorsubstrate so as to cover the photodiodes. Then, the color filters areformed on the insulating film, and the on-chip lenses are formed on thecolor filters.

Here, in the step of forming the color filters, the layout including thefirst, second, and third pixel combinations 1, 2, and 3 is employed. Inthe first pixel combination 1, two green pixels are arranged both in thehorizontal and vertical directions as the color filters, and a total offour pixels are arranged while provided with a green color filter astheir color filter. In the second pixel combination 2, two blue pixelsare arranged both in the horizontal and vertical directions, and a totalof four pixels are arranged while provided with a blue color filter. Inthe third pixel combination 3, two red pixels are arranged both in thehorizontal and vertical directions, and a total of four pixels arearranged while provided with a red color filter. The fourth pixelcombinations 4, in which the first pixel combinations 1 and the secondpixel combinations 2 are alternately arranged in the horizontaldirection, and the fifth pixel combinations 5, in which the first pixelcombinations 1 and the third pixel combinations 3 are alternatelyarranged in the horizontal direction, are alternately arranged in thevertical direction so as to shift by the amount of the first pixelcombination 1 in the horizontal direction.

In the step of forming the on-chip lenses, one on-chip lens is formedfor each of the first, second, and third pixel combinations 1, 2, and 3as the on-chip lenses.

As described above, four adjacent green pixels constitute the firstpixel combination 1, and no overlapping portion comes about in the firstpixel combination 1. Accordingly, it is possible to manufacture thesolid-state imaging device capable of reducing the area of thenon-effective regions and enhancing sensitivity. Particularly, since theadjacent blue pixels and the adjacent red pixels respectively form thesecond pixel combination 2 and the third pixel combination 3, nooverlapping portion comes about in the second pixel combination 2 andthe third pixel combination 3. Accordingly, it is possible to reduce thearea of the non-effective regions and enhance sensitivity.

In addition, it is possible to secure the large opening sizes of theoptical waveguides and thereby to enhance the light collection effect byforming one optical waveguide for each first pixel combination 1 as theoptical waveguide for the green pixels. Moreover, it is possible tosecure the large opening sizes of the optical waveguides and thereby toenhance the light collection effect by forming one optical waveguide foreach four blue pixels and each four red pixels in the same manner.

Third Embodiment

[Configuration in Which Floating Diffusion is Shared]

FIG. 7A is a plan view illustrating the pixel layout of the solid-stateimaging device according to this embodiment.

The solid-state imaging device according to this embodiment is a CMOSimage sensor.

The pixel layout and the on-chip lens layout are the same as those inthe first embodiment. These may be the same as those in the firstmodified example, the second modified example, or the second embodiment.

The CMOS image sensor is provided with a MOS transistor which is calleda floating diffusion and a source follower for each pixel, which will bedescribed later. Here, in the configuration according to thisembodiment, the circuits after the floating diffusion are shared by aplurality of pixels.

As shown in FIG. 7A, a floating diffusion FD is formed for a total offour pixels, that is, two green pixels G, one blue pixel B, and one redpixel R. The above four pixels are connected to the floating diffusionthrough respective transfer transistors. That is, the drawing shows theconfiguration in which one floating diffusion is shared by four pixels.

FIG. 7B is an equivalent circuit diagram of the pixels in the case wherea floating diffusion is shared by a plurality of pixels in thesolid-state imaging device according to this embodiment. FIG. 7B showsthe case in which one floating diffusion is shared by two pixels.

For example, a photodiode 33 is formed in a pixel 31, and connected tothe floating diffusion FD through a transfer transistor 35.

In the same manner, a photodiode 34 is formed in the other pixel 32, andconnected to the floating diffusion FD through the transfer transistor36.

Control lines (42, 43) connected to the gates of the transfertransistors (35, 36) controls the ON and OFF states of the respectivetransfer transistors (35, 36), and the signal charge charged in thephotodiodes (33, 34) is transferred to the floating diffusion FD.

A gate electrode of an amplification transistor 38, which is called asource follower, is connected to the floating diffusion FD, and theoutput in accordance with the amount of the electric charge of thefloating diffusion FD is output from an output line 40.

In addition, a reset transistor 37 is connected to the floatingdiffusion FD, and it is possible to remove and reset the signal chargefrom the floating diffusion after completing the reading by turning onand off the reset transistor 37.

In the above operations, by sequentially executing the transferring bythe transfer transistor, the reading of the signal, and the resettingoperation for each pixel, it is possible to obtain the signal of eachpixel even if the floating diffusion is shared by a plurality of pixels.

[Layout of Photodiodes in Accordance with Sizes of On-Chip Lenses]

FIG. 8 is a plan view enlarging the four pixels shown in FIG. 7A, whichare two green pixels G, one blue pixel B, and one red pixel R, and thefloating diffusion FD formed so as to be surrounded by the four pixels.Each pixel is respectively provided with a photodiode (PD_(G), PD_(B),or PD_(R)).

The photodiodes (PD_(G), PD_(B), PD_(R)) are connected to the floatingdiffusion FD through the transfer transistors each having a transfergate (G_(G), G_(B), or G_(R)). One floating diffusion is shared by fourpixels.

In the above configuration, the on-chip lens (OCL_(B) or OCL_(R)) isformed for each pixel of the blue pixel B and the red pixel R. On theother hand, one on-chip lens OCL_(G) shared by a pixel combinationconstituted by four green pixels G is formed for the green pixels G. Theon-chip lens has a light collection efficiency which is higher in thecenter portion thereof and becomes lower in the periphery portionthereof.

It is preferable that the photodiodes (PD_(B), PD_(R)) for the bluepixel B and the red pixel R are respectively provided at the centers ofthe blue pixel B and the red pixel R.

On the other hand, the photodiodes PD_(G) for the green pixels G arepreferably provided not at the centers of the pixels but at thepositions closer to the centers of the on-chip lenses OCL_(G) ascompared with the positions of the photodiodes (PD_(B), PD_(R)) for theblue pixel B and the red pixel R as shown in FIG. 8.

When the positions of the photodiodes are different for each pixel asdescribed above, it is preferable to employ in the layout, the floatingdiffusion FD with a form extending to the photodiodes PD_(G) for thegreen pixels G as shown in FIG. 8. The transfer gates (G_(G), G_(B),G_(R)) are formed in the regions between the floating diffusion FD withthe above-described form and the respective photodiodes (PD_(G), PD_(B),PD_(R)), and the transfer transistors are configured.

Other components are the same as those in the first embodiment.Alternatively, these may be the same as those in the first modifiedexample, the second modified example, or the second embodiment.

As described above, according to the color filters of this embodiment,four adjacent green pixels constitute the first pixel combination 1, andno overlapping portion comes about in the first pixel combination 1.Accordingly, it is possible to reduce the area of the non-effectiveregions and enhance sensitivity. Particularly, the green light is alight in a region for which people's eyes have high sensitivity.Therefore, it is possible to enhance luminance data of the obtainedimage data by improving the sensitivity of the green pixels.

In addition, it is possible to secure the large opening sizes of theoptical waveguides and thereby to enhance the light collection effect byforming one optical waveguide for each first pixel combination 1 as theoptical waveguide for the green pixels.

Fourth Embodiment

[Configuration of Upper Layer Wiring]

FIG. 9 is a plan view illustrating the pixel layout of the solid-stateimaging device according to this embodiment.

The layout of the pixels and the on-chip lenses are the same as those inthe first embodiment. Alternatively, these may be the same as those inthe first modified example, the second modified example, or the secondembodiment. In addition, when the solid-state imaging device is a CMOSimage sensor, the configuration thereof may be the same as that in thethird embodiment.

As shown in FIG. 2A of the first embodiment, the first insulating film13 is formed on the semiconductor substrate so as to cover thephotodiodes. The conductive layers 14 constituting the upper layerwiring are embedded in the first insulating film 13 above the region inwhich the separation insulating films 11 are formed.

The above conductive layer 14 is made of metal which does not transmitlight or of polysilicon which has low light permeability. Accordingly,the light incident on the photodiodes for the pixels was not disturbedin the border portions between pixels according to the related art.According to this embodiment, however, four adjacent green pixelsconstitute the first pixel combination 1, and there is a possibilitythat the conductive layers disturb the light incident on the positionsin which the conductive layers are provided so as to cross over thepixels in the first pixel combinations 1 even if the positionscorrespond to the border portions of the pixels.

Thus, according to this embodiment, the conductive layer W as the upperlayer wiring is positioned so as not to cross over the pixels in eachfirst pixel combination 1 as shown in FIG. 9. Specifically, theconductive layers are positioned in the border portions between thefirst pixel combinations 1 and the second pixel combinations 2.

With the above configuration, it is possible to reduce the possibilitythat the conductive layers W as the upper layer wirings disturb thelight incident on the photodiodes.

Other components may be the same as those in each embodiment or eachmodified example.

Fifth Embodiment

[Configuration in Which Pluralities of Green Pixels are Arranged inFirst and Second Directions]

FIG. 10 is a plan view illustrating the pixel layout of the solid-stateimaging device according to this embodiment.

The green pixels G, the blue pixels B, and the red pixels R arerespectively arranged as shown in FIG. 10. Each pixel is arranged in thefirst and the second directions which are inclined by 45° from thegeneral horizontal and vertical directions.

Here, a plurality of green pixels G having green color filters arearranged both in the first and second directions as the color filters.The blue pixels B and the red pixels R are entirely surrounded by thegreen pixels G.

In addition, the on-chip lens shared by a plurality of green pixels isformed as the on-chip lens. The number of pixels may be any number aslong as it is more than one. Moreover, the on-chip lens may be separatedat appropriate positions.

In addition, the optical waveguide for the green pixels may be formed soas to be communicated with by a plurality of pixels.

According in the solid-state imaging device with the above-describedlayout, it is possible to enlarge the size of each pixel withoutdegrading the quality of the obtained image data, and to thereby enhancesensitivity.

First Working Example

The solid-state imaging device including the pixels arranged in thelayout shown in FIG. 11 is assumed while following the first embodiment.

In the layout shown in FIG. 11, the green pixels G, the blue pixels B,and the red pixels R are arranged in B11 to G68.

In the above configuration, the blue signals and the red signals in thegreen pixels G35, G36, G45, and G46 can be obtained by calculating fromthe data of the blue signals and the red signals of the pixels, whichexist in the periphery of each pixel, as follows:R36=(R16+R56)/2,R46=(R44+R48)/2B36=(B34+B38)/2,B46=(B26+B66)/2R35=(R33+R37)/2,R45=(R25+R65)/2B35=(B15+B55)/2,B45=(B43+B47)/2  [Equation 1]

The green signals in the red pixels R33 and R44 and the blue pixels B34and B43 can be obtained by calculating from the date of the greensignals of the pixels, which exist in the periphery of each pixel.G34=(G14+G54+G32+G36)/4,G44=(G24+G64+G42+G46)/4G33=(G13+G53+G31+G35)/4,G43=(G23+G63+G41+G45)/4  [Equation 2]

Second Working Example

The solid-state imaging device including the pixels arranged in thelayout shown in FIG. 12 is assumed while following the first modifiedexample.

In the layout shown in FIG. 12, the green pixels G, the blue pixels B,and the red pixels R are arranged in R11 to G68.

In the above configuration, the blue signals and the red signals in thegreen pixels G35, G36, G45, and G46 can be obtained by calculating fromthe data of the blue signals and the red signals of the pixels, whichexist in the periphery of each pixel, as follows:R36=(R34+R38)/2,R46=(R26+R66)/2B36=(B16+B56)/2,B46=(B44+B48)/2R35=(R15+R55)/2,R45=(R43+R47)/2B35=(B33+B37)/2,B45=(B25+B65)/2  [Equation 3]

In addition, the green signals in the blue pixels B33 and B44 and thered pixels R34 and R43 can be obtained by calculating from the data ofthe green signals of the pixels, which exist in the periphery of eachpixel.G34=(G14+G54+G32+G36)/4,G44=(G24+G64+G42+G46)/4G33=(G13+G53+G31+G35)/4,G43=(G23+G63+G41+G45)/4  [Equation 4]

Third Working Example

The solid-state imaging device including the pixels arranged in thelayout shown in FIG. 13 is assumed while following the second modifiedexample.

In the layout shown in FIG. 13, the green pixels G, the blue pixels B,and the red pixels R are arranged in R11 to G68.

In the above configuration, the blue signals and the red signals in thegreen pixels G35, G36, G45, and G46 can be obtained by calculating fromthe data of the blue signals and the red signals of the pixels, whichexist in the periphery of each pixel, as follows:B36=(B25+B47)/2,R46=(R37+R55)/2R35=(R26+R44)/2,B45=(B34+B56)/2  [Equation 5]

In addition, the green signals in the red pixels R33 and R44 and theblue pixels B34 and B43 can be obtained by calculating from the data ofthe green signals of the pixels, which exist in the periphery of eachpixel.G34=(G14+G54+G32+G36)/4,G44=(G24+G64+G42+G46)/4G33=(G13+G53+G31+G35)/4,G43=(G23+G63+G41+G45)/4  [Equation 6]

Fourth Working Example

The solid-state imaging device including the pixels arranged in thelayout shown in FIG. 14 is assumed while following the secondembodiment.

In the layout shown in FIG. 14, the green pixels G, the blue pixels B,and the red pixels R are arranged in R11 to G68.

In the above configuration, the blue signals and the red signals in thegreen pixels G35, G36, G45, and G46 can be obtained by calculating fromthe data of the blue signals and the red signals of the pixels, whichexist in the periphery of each pixel, as follows:R36=(R16+R56)/2,R46=(R44+R48)/2B36=(B34+B38)/2,B46=(B26+B66)/2R35=(R33+R37)/2,R45=(R25+R65)/2B35=(B15+B55)/2,B45=(B43+B47)/2  [Equation 7]

In addition, the green signals in the blue pixels B33, B34, B43 and B44can be obtained by calculating from the data of the green signals of thepixels, which exist in the periphery of each pixel.G34=(G14+G54+G32+G36)/4,G44=(G24+G64+G42+G46)/4G33=(G13+G53+G31+G35)/4,G43=(G23+G63+G41+G45)/4  [Equation 6]

Sixth Embodiment

[Camera Employing Solid-State Imaging Device]

FIG. 15 is a schematic configuration diagram of the camera according tothis embodiment.

This camera is provided with a solid-state imaging device 50 in which aplurality of pixels are integrated, an optical system 51, and a signalprocessing circuit 53.

In this embodiment, the above solid-state imaging device 50 includes thesolid-state imaging device according to any one of the first to fifthembodiments and the first and second modified examples.

The optical system 51 forms an image on the imaging surface of thesolid-state imaging device 50 by the imaging light (incident light) fromthe object. As a result, the photodiode constituting each pixel on theimaging surface of the solid-state imaging device 50 converts theimaging light into the signal charge in accordance with the incidentlight amount, and charges the signal charge for a predetermined timeperiod.

The charged signal charge is output as an output signal Vout through aCCD charge channel, for example.

The signal processing circuit 53 subjects the output signal Vout of thesolid-state imaging device 50 to various signal processings, and outputsas a video signal.

According to the above-described camera of this embodiment, it ispossible to improve the color shading characteristic and the dispersioncharacteristic without lowering the light collection ratio of theobliquely incident light and enhance sensitivity. Moreover, it ispossible to form the microlens with a simple method and simpleprocesses.

The embodiments of the present invention are not limited to the abovedescription.

For example, the embodiments can be applied to both the CMOS sensor andthe CCD element.

In addition, various modifications can be made without departing fromthe scope of the present invention.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2009-173127 filedin the Japan Patent Office on Jul. 24, 2009, the entire content of whichis hereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A solid-state imaging device comprising: aplurality of pixels; photodiodes which are formed separately forrespective ones of the pixels arranged in a matrix shape on a lightsensing surface of a semiconductor substrate; a signal reading unitwhich is formed on the semiconductor substrate and reads a signal chargegenerated and charged in the photodiodes or a voltage in accordance withthe signal charge; an insulating film which is formed on thesemiconductor substrate so as to cover the photodiodes and includesoptical waveguides; color filters which are formed on the insulatingfilm; and on-chip lenses which are formed on the color filters, whereinin a layout, first pixel combinations and second pixel combinations arealternately arranged both in horizontal and vertical directions, thefirst pixel combination having a layout in which two green pixels arearranged both in the horizontal and vertical directions and a total offour pixels are arranged while provided with a green color filter astheir color filter, the second pixel combination having a layout inwhich two pixels are arranged both in the horizontal and verticaldirections, a total of four pixels are arranged, and two red pixelshaving red color filters and two blue pixels having blue color filtersare arranged so that the two red pixels and the two blue pixels arediagonally placed.
 2. The solid-state imaging device according to claim1, wherein one on-chip lens is formed for each first pixel combinationas the on-chip lens.
 3. The solid-state imaging device according toclaim 2, wherein one on-chip lens is formed for each pixel of the secondpixel combination as the on-chip lens, and a diameter of one on-chiplens for each pixel of the second pixel combination is different fromthat of one on-chip lens for the first pixel combination.
 4. Thesolid-state imaging device according to claim 1, wherein one opticalwaveguide is formed for each first pixel combination as the opticalwaveguide.
 5. The solid-state imaging device according to claim 4,wherein one optical waveguide is formed for each pixel of the secondpixel combination as the optical waveguide, and one opening size of theoptical waveguide for each pixel of the second pixel combination isdifferent from that of the optical waveguide for the first pixelcombination.
 6. The solid-state imaging device according to claim 1,wherein wirings are embedded in the insulating film, and wherein thewirings are arranged so as not to cross over a region of the first pixelcombination.
 7. A solid-state imaging device comprising: a plurality ofpixels, photodiodes which are formed separately for respective ones ofthe pixels arranged in a matrix shape on a light sensing surface of asemiconductor substrate; a signal reading unit which is formed on thesemiconductor substrate and reads a signal charge generated and chargedin the photodiodes or a voltage in accordance with the signal charge; aninsulating film which is formed on the semiconductor substrate so as tocover the photodiodes and includes optical waveguides; color filterswhich are formed on the insulating film; and on-chip lenses which areformed on the color filters, wherein color filters include first pixelcombinations in each of which two green pixels are arranged both inhorizontal and vertical directions and a total of four pixels arearranged while provided with a green color filter as their color filter,second pixel combinations in each of which two blue pixels are arrangedboth in the horizontal and vertical directions and a total of fourpixels are arranged while provided with a blue color filter as theircolor filter, and third pixel combinations in each of which two redpixels are arranged both in the horizontal and vertical directions and atotal of four pixels are arranged while provided with a red color filteras their color filter, wherein in a layout, fourth pixel combinations,in each of which the first pixel combinations and the second pixelcombinations are alternately arranged in the horizontal direction, andfifth pixel combinations, in each of which the first pixel combinationsand the third pixel combinations are alternately arranged in thehorizontal direction, are alternately arranged in the vertical directionso as to shift by the amount of the first pixel combination in thehorizontal direction, and wherein one on-chip lens is formed for each ofthe first pixel combination, the second pixel combination, and the thirdpixel combination as the on-chip lens.
 8. The solid-state imaging deviceaccording to claim 7, wherein one optical waveguide is formed for eachfirst pixel combination as the optical waveguide.
 9. The solid-stateimaging device according to claim 8, wherein one optical waveguide isformed for each of the second pixel combination and the third pixelcombination as the optical waveguide.
 10. The solid-state imaging deviceaccording to claim 7, wherein wirings are embedded in the insulatingfilm, and wherein the wirings are arranged so as not to cross over aregion of the first pixel combination.
 11. A method of manufacturing asolid-state imaging device comprising the steps of: forming photodiodesseparately for respective pixels arranged in a matrix shape on a lightsensing surface of a semiconductor substrate and a signal reading unitfor reading a signal charge generated and charged in the photodiodes ora voltage in accordance with the signal charge; forming an insulatingfilm including optical waveguides on the semiconductor substrate so asto cover the photodiodes; forming color filters on the insulating film;and forming on-chip lenses on the color filters, wherein in the step offorming the color filters, a layout in which first pixel combinationsand second pixel combinations are alternately arranged both inhorizontal and vertical directions is employed, the first pixelcombination having a layout in which two green pixels are arranged bothin the horizontal and vertical directions and a total of four pixels arearranged while provided with a green color filter as their color filter,the second pixel combination having a layout in which two pixels arearranged both in the horizontal and vertical directions, a total of fourpixels are arranged, and two red pixels having red color filters and twoblue pixels having blue color filters are arranged so that the two redpixels and the two blue pixels are diagonally placed.
 12. A method ofmanufacturing a solid-state imaging device comprising the steps of:forming photodiodes separately for respective pixels arranged in amatrix shape on a light sensing surface of a semiconductor substrate anda signal reading unit for reading a signal charge generated and chargedin the photodiodes or a voltage in accordance with the signal charge;forming an insulating film including optical waveguides on thesemiconductor substrate so as to cover the photodiodes; forming colorfilters on the insulating film; and forming on-chip lenses on the colorfilters, wherein in the step of forming the color filters, the colorfilters include first pixel combinations, in each of which two greenpixels are arranged both in horizontal and vertical directions and atotal of four pixels are arranged while provided with a green colorfilter as their color filter, second pixel combinations, in each ofwhich two blue pixels are arranged both in the horizontal and verticaldirections and a total of four pixels are arranged while provided with ablue color filter as their color filter, and third pixel combinations,in each of which two red pixels are arranged both in the horizontal andvertical directions and a total of four pixels are arranged whileprovided with a red color filter as their color filter, wherein in alayout, fourth pixel combinations, in each of which the first pixelcombinations and the second pixel combinations are alternately arrangedin the horizontal direction, and fifth pixel combinations, in each ofwhich the first pixel combinations and the third pixel combinations arealternately arranged in the horizontal direction, are alternatelyarranged in the vertical direction so as to shift by the amount of thefirst pixel combination in the horizontal direction, and wherein in thestep of forming the on-chip lens, one on-chip lens is formed for each ofthe first pixel combination, the second pixel combination, and the thirdpixel combination as the on-chip lens.
 13. A camera comprising: asolid-state imaging device in which a plurality of pixels are integratedon a light sensing surface; an optical system which guides incidentlight to an imaging unit of the solid-state imaging device; and a signalprocessing circuit which processes output signals of the solid-stateimaging device, wherein the solid-state imaging device includes aplurality of pixels; photodiodes which are formed separately forrespective ones of the pixels arranged in a matrix shape on a lightsensing surface of a semiconductor substrate, a signal reading unitwhich is formed on the semiconductor substrate and reads a signal chargegenerated and charged in the photodiodes or a voltage in accordance withthe signal charge, an insulating film which is formed on thesemiconductor substrate so as to cover the photodiodes and includesoptical waveguides, color filters which are formed on the insulatingfilm, and on-chip lenses which are formed on the color filters, andwherein in a layout of the color filters, first pixel combinations andsecond pixel combinations are alternately arranged both in horizontaland vertical directions, the first pixel combination having a layout inwhich two green pixels are arranged both in the horizontal and verticaldirections and a total of four pixels are arranged while provided with agreen color filter as their color filter, the second pixel combinationhaving a layout in which two pixels are arranged both in the horizontaland vertical directions, a total of four pixels are arranged, and twored pixels having red color filters and two blue pixels having bluecolor filters are arranged so that the two red pixels and the two bluepixels are diagonally placed.
 14. A camera comprising: a solid-stateimaging device in which a plurality of pixels are integrated on a lightsensing surface of a semiconductor substrate; an optical system whichguides incident light to an imaging unit of the solid-state imagingdevice; and a signal processing circuit which processes output signalsof the solid-state imaging device, wherein the solid-state imagingdevice includes photodiodes which are formed separately for respectiveones of the pixels arranged in a matrix shape on the light sensingsurface of the semiconductor substrate, a signal reading unit which isformed on the semiconductor substrate and reads a signal chargegenerated and charged in the photodiodes or a voltage in accordance withthe signal charge, an insulating film which is formed on thesemiconductor substrate so as to cover the photodiodes and includesoptical waveguides, color filters which are formed on the insulatingfilm, and on-chip lenses which are formed on the color filters, whereincolor filters include first pixel combinations in each of which twogreen pixels are arranged both in horizontal and vertical directions anda total of four pixels are arranged while provided with a green colorfilter as their color filter, second pixel combinations in each of whichtwo blue pixels are arranged both in the horizontal and verticaldirections and a total of four pixels are arranged while provided with ablue color filter as their color filter, and third pixel combinations ineach of which two red are arranged both in the horizontal and verticaldirections and a total of four pixels are arranged while provided with ared color filter as their color filter, wherein in a layout, fourthpixel combinations, in each of which the first pixel combinations andthe second pixel combinations are alternately arranged in the horizontaldirection, and fifth pixel combinations, in each of which the firstpixel combinations and the third pixel combinations are alternatelyarranged in the horizontal direction, are alternately arranged in thevertical direction so as to shift by the amount of the first pixelcombination in the horizontal direction, and wherein one on-chip lens isformed for each of the first pixel combination, the second pixelcombination, and the third pixel combination as the on-chip lens.